Acoustic wave biosensor for the detection of the breast and prostate cancer metastasis biomarker protein PTHrP

Biosens Bioelectron. 2016 Apr 15:78:92-99. doi: 10.1016/j.bios.2015.11.031. Epub 2015 Nov 12.

Abstract

There are currently no biosensors that are able to reliably detect the process of cancer metastasis. We describe the first label-free real-time ultra-high frequency acoustic wave biosensor prototype capable of detecting the breast and prostate cancer metastasis biomarker, parathyroid hormone-related peptide (PTHrP). Two different linkers - 11-trichlorosilyl-undecanoic acid pentafluorophenyl ester (PFP) and S-(11-trichlorosilyl-undecanyl)-benzothiosulfonate (TUBTS) - were used to immobilize whole anti-PTHrP antibodies and Fab' fragments to surfaces as biorecognition elements. The biosensor surfaces were optimized using X-ray photoelectron spectroscopy (XPS) and the ultra-high frequency electromagnetic piezoelectric acoustic sensor (EMPAS). One optimized whole antibody-based surface (PFP/protein G'/whole antibodies/ethanolamine) and one optimized Fab' fragment-based surface (TUBTS/Fab' fragments) were tested as biosensors. It was determined that an in-line injection of bovine serum albumin prior to analyte injection yielded the most minimally fouling surfaces. Each surface was tested with no mass amplification and with sandwich-type secondary antibody mass amplification. The whole antibody-based mass-amplified biosensor yielded the lowest limit of detection (61 ng/mL), highest sensitivity, and a linear range from 61 ng/mL to 100 μg/mL. However, the Fab' fragment-based biosensor displayed better regenerability as a loss of ~20% of the initial analyte signal intensity was observed with each subsequent injection. The whole antibody-based biosensor was only capable of producing an analyte signal in the first injection.

Keywords: Acoustic wave sensor; Antibodies; Biosensor; Cancer metastasis; Fab' fragments; Parathyroid hormone-related peptide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Immobilized / chemistry
  • Antibodies, Immobilized / immunology
  • Biosensing Techniques*
  • Breast Neoplasms / diagnosis*
  • Cattle
  • Female
  • Fluorobenzenes / chemistry
  • Humans
  • Immunoglobulin Fab Fragments / chemistry
  • Immunoglobulin Fab Fragments / immunology
  • Male
  • Neoplasm Metastasis
  • Parathyroid Hormone-Related Protein / isolation & purification*
  • Phenols / chemistry
  • Photoelectron Spectroscopy
  • Prostatic Neoplasms / diagnosis*
  • Serum Albumin, Bovine / chemistry
  • Serum Albumin, Bovine / immunology
  • Sound

Substances

  • Antibodies, Immobilized
  • Fluorobenzenes
  • Immunoglobulin Fab Fragments
  • Parathyroid Hormone-Related Protein
  • Phenols
  • Serum Albumin, Bovine
  • 2,3,4,5,6-pentafluorophenol